Transcriptome Profiling of Human Prostate Cancer Cell Line LNCaP Treated with IndividualSoy Isoflavones or Their Combination

Abstract

Prostate cancer (PCa) is the second leading cause of cancer death in American men. Increasing epidemiologic evidence and laboratory studies suggest soy isoflavones might reduce PCa risk. However, attention has been drawn to the safety of using high levels of soy isoflavones in human, which is especially the concern about taking soy isoflavone dietary supplements. Our previous work showed that daidzein and genistein had a synergistic effect on inhibiting proliferation and inducing apoptosis of PCa cells, which suggests a combination of isoflavones at lower levels may be more effective for PCa prevention. Based on this work, RNA sequencing (RNA‐seq) was performed in this study to search underlying mechanisms in human prostate cancer cell line LNCaP treated with individual isoflavones (genistein or daidzein, 50 or 200 μM) or their combination (50 μM). Transcriptome analysis showed that several genes were differently expressed in LNCap cells among treatments with individual isoflavones or their combination.Genes such as transcription factor CP2‐like 1, activating transcription factor 3, PRKC apoptosis WT1 regulator, DNA‐damage‐inducible transcript 3 and interferon gamma‐inducible protein 16 are highly expressedin the cells treated with genistein orthecombination of daidzein and genistein, while not highly expressed in the cells treated only with daidzein. To conclude, these findings have indicated that RNA‐seq is valuable to simultaneously search multiple molecular targets involved in the cancer preventive effect of soy isoflavones and a reliable means to quantify absolute transcript levels. The findings might also help explain the synergistic effect of daidzein and genistein.The project is funded by University of Delaware Research Foundation.